1. Field of the Invention
The present invention is directed to a high-loft nonwoven including a binder or stabilizer including a polyurethaneurea composition that provides flexibility and compression recovery to the nonwoven structure. Included is a polyurethaneurea dispersion as a stabilizer or binder for the short-length fibers which create the high-loft nonwoven structure. The invention is useful as an improved alternative for such things as polyurethane foam in applications such as bra cups.
2. Summary of the Related Technology
Most bras are made with some form of padding in the cup. Padding is used for shape and size enhancement as well as for modesty purposes. Fiberfill was used in the past to form bra cup padding, but because the fibers could migrate within the cup, particularly during laundering, the cups would become misshapen or lumpy.
As padded bras increased in popularity, bra manufacturers began using polyurethane (PU) foam as an alternative to fiberfill. PU foam has enjoyed a massive substitution for fiberfill. While PU foam is soft, light, and can be shaped by molding, PU foam has a major deficiency which is yellowing due to oxidation and/or photochemical reaction. Manufacturers, at considerable expense (such as using multiple layers of fabric), design bras in such a way as to conceal PU foam in order to disguise the yellowing. In addition, PU foam lacks has poor breatheability, permeability, and vapor transmission characteristics.
U.S. Pat. No. 3,947,207 to Magidson, et al. recognizes the challenges associated with preparing a padded bra cup that maintains its shape after repeated washings. The fiberfill pads include a resin binder that is nearly fully cured prior to stretching forming the pads to the desired shape. In order to compensate for this, an additional polyurethane resin is applied. The disadvantage is that the polyurethane imparts a stiffness to the bra pad which is uncomfortable to the wearer. This alternative was not commercially acceptable which is one reason why the switch to PU foam was made.
U.S. Pat. No. 4,091,819 to Huber et al. also discloses a padded bra cup including a fiberfill padding. A resin binder such as an acrylic, polyester, acetate or combinations thereof are added to the padding to increase shape retention during washing. The problems associated with stiffness of the padding are recognized and compensated for by perforating the padding after the introduction of the resin. Although this provides an increase in flexibility, this is a costly step and does not provide an adequate solution to the comfort issue.
U.S. Pat. No. 6,670,035 to Pittman et al. discloses binder fiber with a non-woven web that includes a low-melt binder fiber. However, such compositions are not suitable for molded applications since they would result in a hard molded article.
Therefore, there is a need for an alternative high loft nonwoven material which maintains its shape after washing, but also provides benefits of flexibility and compression recovery that are essential for wearer comfort.